In an unprecedented display of people power against the war on drugs, thousands of activists in 100 cities across the world will rally on Thursday, June 26, to push one message: “Support. Don’t punish.”

The concerted campaign will remind national governments and the UN of the growing size and clout of people who use drugs and their supporters as a political constituency—and the futility of pouring billions of dollars into efforts to enforce prohibition.

At least 150 NGOs will be involved worldwide, either as active organizers or as supporters, but the London-based International Drug Policy Consortium (IDPC) is acting as the hub. Jamie Bridge, the IDPC’s senior policy and operations manager, tells Substance.com that the momentum building behind the day of action is “a sign that people do want to mobilize behind this kind of message.”

The global day of action first took place last year but will more than double in size for 2014, thanks to a more aggressive recruitment policy and the support of big organizations like the New York-based Open Society Foundations. Niamh Eastwood, executive director of Release, a UK organization campaigning for drug policy reform, recalls that last year’s events ranged in scale and scope from “a small number of marginalized drug users in India, standing with signs saying ‘Support. Don’t punish,’ which was deeply moving,” to a “much more elaborate event involving street art and dancers” in Romania.

June 26 is the date because it’s when the UN holds its International Day Against Drug Abuse and Illicit Trafficking. Sickeningly, governments of countries including China and Indonesia have been known to mark the day with the executions and torture of drug offenders. Drug policy reform activists want to reclaim the date. For too long, says Bridge, “governments have taken it upon themselves to celebrate fighting this war on drugs. There’s not a lot to celebrate.”